This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. (A) OVERALL AIMS The overall aims of this project are to collaborate with the NBCR investigators to: (1) advance mathematical models from the cardiac myocyte level to more integrative whole heart models, and (2) to develop more detailed subcellular cardiac myocyte models at the level of local molecular environments. This will build on the cardiac myocyte cellular models that we are developing in a dynamic feedback with experimental data that is at the core of several grant-funded projects. It will also synergize with multiscale modeling efforts which are a central component of Dr. McCulloch's ongoing projects and of the NBCR Core projects [4A.1A] and [4A.2B].